It is generally known and typical in the construction and operation of aircraft, that the high lift landing flaps and slats arranged on the wings are driven by means of a transmission system from a centrally arranged drive unit. In this manner, the drive power of a single drive unit can be used to operate a plurality of flaps and slats or the like, without requiring a plurality of separate drive motors. In this context, the overall drive system comprises a drive motor, redirecting or transfer transmissions, actuators, and plural transmissions shafts, as well as support bearings, articulated joints, and shaft couplings associated with the shafts.
FIG. 1 schematically shows a general overview of a known arrangement of a drive system for driving the flaps 51 and slats 52 arranged in a wing 5 of an aircraft 50. The flap and slat drive system includes a transmission system 1 that is driven or powered by a central drive unit 25. The transmission system 1 includes transmission shafts 8 respectively coupled together by coupling elements 2 at locations where the shaft run is substantially straight, and by articulated joint elements 4 at locations where the shaft run passes through a bend or the like. Additionally, respective coupling elements 2, which may also provide a limited flexibility, and the articulated joint elements 4 must respectively be arranged at each location where the transmission system 1 is supported by support bearings 3 or connected to redirecting or transfer transmissions 26 or to actuators 27. In this context, the particular type of coupling element or joint element is selected depending on the magnitude of the bend or redirection of the shaft line at that location. It is necessary to provide a flexible joint at each support bearing, in order to avoid the introduction of external bending forces into the shafts due to the flexing of the wing 5.
Although flexible shaft couplings in general are known in the art, there has been a continuing need for improving the safety, reliability, and simplicity, and reducing the size and weight of such couplings, while achieving a more robust arrangement with a reduced need for maintenance, which may be used uniformly for many different installation situations throughout the transmission system.